Sponge filter seeding

Hi all

I have a teeny Nano tank 4 Gallon that currently has one of those nasty seethrough plastic Corner filters in it that came seeded with the cycled tank I bought. I am planning of setting up a fully planted tank for my Betta (will be alone in it) but the thing is firstly really ugly and imo fairly useless. Secondly I have bought a sponge filter to be used instead but don’t know how to go about the swop. I know I can’t just swop it out.

I plan to drain the tank and clean it before adding new substrate and the plants too. So I know the filter will need to go back at first. I currently have the sponge wedged over the outlet of the old filter to start seeding but it takes up even more space and I am not sure how long I need to wait to actually make the swop?

The image is the tank now.

 

I'd run that Sponge filter in your most established and most stocked tank for at least 2 weeks.

 

Thank you. I have done as you suggested. I stuck the Sponge i to the Canister Uptake to use as a Prefilter. I thought about putting it into the Canister but decided not to because after just recently getting it working I didn’t feel like taking ut apart again so quickly.